08 Dec, 2017

2 commits

  • Now that the SPDX tag is in all driver core files, that identifies the
    license in a specific and legally-defined manner. So the extra GPL text
    wording can be removed as it is no longer needed at all.

    This is done on a quest to remove the 700+ different ways that files in
    the kernel describe the GPL license text. And there's unneeded stuff
    like the address (sometimes incorrect) for the FSF which is never
    needed.

    No copyright headers or other non-license-description text was removed.

    Cc: Johannes Berg
    Cc: "Luis R. Rodriguez"
    Signed-off-by: Greg Kroah-Hartman

    Greg Kroah-Hartman
     
  • It's good to have SPDX identifiers in all files to make it easier to
    audit the kernel tree for correct licenses.

    Update the driver core files files with the correct SPDX license
    identifier based on the license text in the file itself. The SPDX
    identifier is a legally binding shorthand, which can be used instead of
    the full boiler plate text.

    This work is based on a script and data from Thomas Gleixner, Philippe
    Ombredanne, and Kate Stewart.

    Cc: Johannes Berg
    Cc: "Luis R. Rodriguez"
    Cc: William Breathitt Gray
    Cc: Thomas Gleixner
    Cc: Kate Stewart
    Cc: Philippe Ombredanne
    Signed-off-by: Greg Kroah-Hartman

    Greg Kroah-Hartman
     

16 Jun, 2016

1 commit

  • Modules which register drivers via standard path (driver_register) in
    parallel can cause a warning:
    WARNING: CPU: 2 PID: 3492 at ../fs/sysfs/dir.c:31 sysfs_warn_dup+0x62/0x80
    sysfs: cannot create duplicate filename '/module/saa7146/drivers'
    Modules linked in: hexium_gemini(+) mxb(+) ...
    ...
    Call Trace:
    ...
    [] sysfs_warn_dup+0x62/0x80
    [] sysfs_create_dir_ns+0x77/0x90
    [] kobject_add_internal+0xb4/0x340
    [] kobject_add+0x68/0xb0
    [] kobject_create_and_add+0x31/0x70
    [] module_add_driver+0xc3/0xd0
    [] bus_add_driver+0x154/0x280
    [] driver_register+0x60/0xe0
    [] __pci_register_driver+0x60/0x70
    [] saa7146_register_extension+0x64/0x90 [saa7146]
    [] hexium_init_module+0x11/0x1000 [hexium_gemini]
    ...

    As can be (mostly) seen, driver_register causes this call sequence:
    -> bus_add_driver
    -> module_add_driver
    -> module_create_drivers_dir
    The last one creates "drivers" directory in /sys/module/. When
    this is done in parallel, the directory is attempted to be created
    twice at the same time.

    This can be easily reproduced by loading mxb and hexium_gemini in
    parallel:
    while :; do
    modprobe mxb &
    modprobe hexium_gemini
    wait
    rmmod mxb hexium_gemini saa7146_vv saa7146
    done

    saa7146 calls pci_register_driver for both mxb and hexium_gemini,
    which means /sys/module/saa7146/drivers is to be created for both of
    them.

    Fix this by a new mutex in module_create_drivers_dir which makes the
    test-and-create "drivers" dir atomic.

    I inverted the condition and removed 'return' to avoid multiple
    unlocks or a goto.

    Signed-off-by: Jiri Slaby
    Fixes: fe480a2675ed (Modules: only add drivers/ direcory if needed)
    Cc: v2.6.21+
    Signed-off-by: Greg Kroah-Hartman

    Jiri Slaby
     

22 May, 2010

1 commit

  • kasprintf combines kmalloc and sprintf, and takes care of the size
    calculation itself.

    The semantic patch that makes this change is as follows:
    (http://coccinelle.lip6.fr/)

    //
    @@
    expression a,flag;
    expression list args;
    statement S;
    @@

    a =
    - \(kmalloc\|kzalloc\)(...,flag)
    + kasprintf(flag,args)

    - sprintf(a,args);
    //

    Signed-off-by: Julia Lawall
    Signed-off-by: Greg Kroah-Hartman

    Julia Lawall
     

30 Mar, 2010

1 commit

  • …it slab.h inclusion from percpu.h

    percpu.h is included by sched.h and module.h and thus ends up being
    included when building most .c files. percpu.h includes slab.h which
    in turn includes gfp.h making everything defined by the two files
    universally available and complicating inclusion dependencies.

    percpu.h -> slab.h dependency is about to be removed. Prepare for
    this change by updating users of gfp and slab facilities include those
    headers directly instead of assuming availability. As this conversion
    needs to touch large number of source files, the following script is
    used as the basis of conversion.

    http://userweb.kernel.org/~tj/misc/slabh-sweep.py

    The script does the followings.

    * Scan files for gfp and slab usages and update includes such that
    only the necessary includes are there. ie. if only gfp is used,
    gfp.h, if slab is used, slab.h.

    * When the script inserts a new include, it looks at the include
    blocks and try to put the new include such that its order conforms
    to its surrounding. It's put in the include block which contains
    core kernel includes, in the same order that the rest are ordered -
    alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
    doesn't seem to be any matching order.

    * If the script can't find a place to put a new include (mostly
    because the file doesn't have fitting include block), it prints out
    an error message indicating which .h file needs to be added to the
    file.

    The conversion was done in the following steps.

    1. The initial automatic conversion of all .c files updated slightly
    over 4000 files, deleting around 700 includes and adding ~480 gfp.h
    and ~3000 slab.h inclusions. The script emitted errors for ~400
    files.

    2. Each error was manually checked. Some didn't need the inclusion,
    some needed manual addition while adding it to implementation .h or
    embedding .c file was more appropriate for others. This step added
    inclusions to around 150 files.

    3. The script was run again and the output was compared to the edits
    from #2 to make sure no file was left behind.

    4. Several build tests were done and a couple of problems were fixed.
    e.g. lib/decompress_*.c used malloc/free() wrappers around slab
    APIs requiring slab.h to be added manually.

    5. The script was run on all .h files but without automatically
    editing them as sprinkling gfp.h and slab.h inclusions around .h
    files could easily lead to inclusion dependency hell. Most gfp.h
    inclusion directives were ignored as stuff from gfp.h was usually
    wildly available and often used in preprocessor macros. Each
    slab.h inclusion directive was examined and added manually as
    necessary.

    6. percpu.h was updated not to include slab.h.

    7. Build test were done on the following configurations and failures
    were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
    distributed build env didn't work with gcov compiles) and a few
    more options had to be turned off depending on archs to make things
    build (like ipr on powerpc/64 which failed due to missing writeq).

    * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
    * powerpc and powerpc64 SMP allmodconfig
    * sparc and sparc64 SMP allmodconfig
    * ia64 SMP allmodconfig
    * s390 SMP allmodconfig
    * alpha SMP allmodconfig
    * um on x86_64 SMP allmodconfig

    8. percpu.h modifications were reverted so that it could be applied as
    a separate patch and serve as bisection point.

    Given the fact that I had only a couple of failures from tests on step
    6, I'm fairly confident about the coverage of this conversion patch.
    If there is a breakage, it's likely to be something in one of the arch
    headers which should be easily discoverable easily on most builds of
    the specific arch.

    Signed-off-by: Tejun Heo <tj@kernel.org>
    Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
    Cc: Ingo Molnar <mingo@redhat.com>
    Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>

    Tejun Heo
     

25 Jan, 2008

2 commits